Linux-audio-dev December 2002

linux-audio-dev@lists.linuxaudio.org

75 participants
96 discussions

by Anthony

Hi, I've been playing a lot with bristol synth and really love it. So much so that I've been trying to 'Jackify' it. Actually, I'm pretty much done, but can't figure out the internal audio format. Its interleaved floats I think, but not normalised to [-1,1]. If any of the developers are here could you help me out? I can hear noise, but I need to tune the maths. TIA. --ant

21 years, 6 months

Re: [linux-audio-dev] Re: image problem [was Re: [Alsa-devel] help for a levelmeter]

by Patrick Shirkey

>> That said, I think Patrick is right to start thinking about this now. Thanks. >I think he's completely right - I'm not sure about this bank account >thing but I do think that now is the time to be demoing, talking up and >generally approaching people and companies about Linux music software. >I wrote us up (and mentioned a few other apps) in the latest edition of >Linux User - John at mstation.org has been very kind so far as well. >Now is the right time to be talking to people and getting the >"products" out there. If it works - why not tell people about it? The reason I believe we need to have various bank accounts are because we cannot afford to waste money on excessive service charges and not everyone has access to credit cards. If we have the accounts in the right countries then people can just donate cash. From a professional perspective we need to show our prospective clients that we have sound financial thinking. It's mostly a subconscious need that consumers have. They want to know that the money they are investing is being given to people/companies/organisations who use it. Most people don't really care how it is used although we have the moral justification on our side too. This is from the Sound on Sound advertising package. "The main target market of Sound On Sound is the professional and semi-professional musician who is the kind of person that will have the spending ability to purchase a large range of products from synthesizers to samplers, mixing desks to microphones, multitracks to monitors, effects to expanders and computer hardware and software. They are not time wasters who do not know their profession - they are serious and mature individuals working with a reasonable budget." If we want to appeal to this audience we need to prove to them that they are investing in professional audio. We need to wine them and dine them (metaphorically). If they look into our commmunity and say these are just amateur geeks who have made some interesting things happen it won't work. If we take the intiative and lead them into our world they will come at it from the perspective that we are professionals who have created a very credible concept that we are proud of and want them to enjoy using. They will ask "What kind of cash have we invested" and if we come back with "Ahh, well we don't actually have a scope on the financial side of our open community." They are just going to look around for a while and leave. If we can show them that not only are we mathematics and logics wizards but that we also have solid business sense then they are going to stick around and see what we have to offer. A lot of them will probably invest just to test the waters or to keep up with the play. I want to see an advertising campaign happen that will educate and encourage the mass of potential user to take the step. I also want to make sure that we have covered our asses when they finally walk in through the doors. It's a choice between being amatuer enthusiasts or professionals. If we come across as professionals people won't give a toss about geekyness. -- Patrick Shirkey - Boost Hardware Ltd. For the discerning hardware connoisseur Http://www.boosthardware.com Http://www.djcj.org - The Linux Audio Users guide ======================================== "Um...symbol_get and symbol_put... They're kindof like does anyone remember like get_symbol and put_symbol I think we used to have..." - Rusty Russell in his talk on the module subsystem

21 years, 7 months

[linux-audio-dev] Audio s/w ui swallowing

by Steve Harris

The world and his dog seems to be releasing macos/windows audio s/w that looks like 19" rack units. Anyone know enough about X to know if its possible to make X apps open thier main window inside a standard sized cabinet (ala Reason). I'm assuming it would be ok to require the app to be a certian size and have explicit support, but I guess it couldn't put any restrictions on toolkit. Other than looking cool, it would actually be a useful way to keep window clutter down. Not that we have any 19" lookalike apps yet, but I guess we will do at some point. - Steve

21 years, 10 months

[linux-audio-dev] XAP: a polemic

by Tim Goetze

this is not meant to intimidate, rather to be a wake-up call. it seems almost unreal (and certainly unprofessional) to me that an instrument plugin api is being discussed here by a bunch of people who have little to no experience in the field of software sequencers. going into implementation details at the current level of understanding of the problem space is, excuse me, ridiculous. after all, what is going to drive your instrument networks? punched cardboard? certainly not. you'll either use realtime input, or a sequencer, or, most wanted, a combination of both. the closer the integration of the event/plugin system with the sequencer, the more uses the api can be put to, with less pain. stopping short of the mark where the api becomes useful for more applications than basically sample-rate dependent event->audio converters is narrow-minded. viewing the 'host' as a blackbox supposed to 'do the rest' without caring about its internals is blatant ignorance. i do think it's reasonable to ignore my personal input since i don't offer published code to back up my views, and when i do, you'll find it centered around my personal musical needs. however there are, afaik, people from the rosegarden team on this list. it would also be helpful having werner schweer of muse fame participate in some way or other. you might also want to look at other free/open sequencer engines. for one thing, you'll find that most, if not all, are tick-based. vst[i] is a bad candidate i think because few people here will have vst host-side coding experience, and the api itself is bound to be centered around the particular coding needs of a specific company, for a specific application that drags code with it that originated in the eighties and never was subject to public source-level review. in short, the more people with hands-on sequencer experience participating, the better. none are just too few. tim ps: if this post hasn't substantially changed your ways of perceiving this matter, please don't bother answering.

21 years, 11 months

[linux-audio-dev] 2.4.20-rc1 + lowlat + preempt + alsa + jack = dead computer

by Fernando Pablo Lopez-Lezcano

[sorry for the wide distribution] Is anyone out there trying out this combination?: kernel 2.4.20-rc1 capabilities patch low latency patch preemptible kernel patch almost current alsa cvs [20021028.170432 usa pacific time] If I start jackd and then use the freqtweak jack client I get a completely dead machine in a very short time (from a few seconds to 10 or 20 seconds). Same alsa driver, but running on 2.4.19 (up to 20-pre4) seems to be fine and I can play around with freqtweak for as long as I want :-) No clues are left behind... something in the kernel is deadlocking, I guess. I tried removing first the preemptible kernel patch with the same result. Just a moment ago I tried again after removing the low latency patch and I still get the same result... that pretty much leaves alsa and the kernel. Got the same result on a laptop intel810 and an ice1712 card. Interestingly enough just the jack server running is not enough to kill the machine. Adding a jack client (just tried alsaplayer, same problem as freqtweak) kills the machine really fast. Maybe there is a problem with the scheduler when there are several SCHED_FIFO tasks competing for the processor? -- Fernando

21 years, 11 months

[linux-audio-dev] [Fwd: ams segmentation fault]

by Eric Dantan Rzewnicki

I don't know whether this is a bug in ams, or a problem with my system...I suspect the later, but can't figure out what's wrong. But, I am unable to get ams to run. It appears to compile OK. But, as noted below, running it results in a "Segmentation fault". I have installed qt3 and fftw. I edited the top of make_ams to match my system: box1:~/audio_code/ams-1.5.5$ head -5 make_ams QT_BASE_DIR=/usr/lib/qt3 QT_LIB_DIR=$(QT_BASE_DIR)/plugins-mt/styles QT_BIN_DIR=/usr/bin QT_INCLUDE_DIR=/usr/include/qt X11_LIB_DIR=/usr/X11R6/lib My ditribution is Debian stable (woody). My system is a PII 400Mhz w/768MB RAM. The version of g++ is 2.95.4. I have a working install of jackd 0.44.0 from cvs. I'm starting jackd like so: # jackd -v -R -d alsa -d ymfpci -r 44100 -zt -n 3 -p 512 I can start up multiple instances of jack_metro, connect them to the alsa ports and hear the beeps. So, jack appears to be working. But, if I start ams nothing is reported in the jackd output about a new client. ams does attempt to connect to the X server when started. I know this because if I 'su -' to get to root and then start ams: box1:/home/eric/audio_code/ams-1.5.5# ./ams ams: cannot connect to X server but, if I su without the dash so that root inherits my user environment ams gets past the point of connecting to the X server (assuming that comes first) and exits with a segmentation fault. I'm not sure what other information would be useful to you in helping me to sort this out. If there is anything else I should tell you, please let me know. Thanks in advance, Eric Rz. -------- Original Message -------- Subject: ams segmentation fault Date: Sat, 28 Dec 2002 21:47:34 -0500 From: Eric Dantan Rzewnicki <eric(a)zhevny.com> Organization: zhevnycom To: Eric Dantan Rzewnicki <rzewnickie(a)rfa.org> CC: linux-audio-user(a)music.columbia.edu References: <3E0BCBEC.9DB82093(a)zhevny.com> <20021227103148.GH681(a)ecs.soton.ac.uk> <1041005858.4921.17.camel@eviltwin> <20021227181307.GD19938(a)rfa.org> Eric Dantan Rzewnicki wrote: > I can now start jackd as root and > then start ams -j. Sorry I didn't think of this earlier. :-\ > > Adding /usr/local/lib to /etc/ld.so.conf and running ldconfig as Steve > suggested allows ams to find libjack.so.0 (I really should have > remembered that piece, too). > > Now that I have it running I'll go finish reading the ams documentation > and figure out how to use it. :) hmm... I perhaps spoke too soon. I had ams working yesterday on one box (at the office)... But, now I can't seem to get it working at home. It seems to compile fine, but when i try to start it: box1:/home/eric/audio_code/ams-1.5.5# ./ams Segmentation fault box1:/home/eric/audio_code/ams-1.5.5# ./ams -j Segmentation fault It doesn't matter if jackd is running or not. Either way it seg faults... What could cause this? What information should I provide to help sort this out? Thanks, Eric Rz.

21 years, 11 months

[linux-audio-dev] 1.5 ms latency possible?

by Anders Torger

I have made a program which is to be run on a dedicated computer, equipped only with a multichannel soundcard (hammerfall), a small LCD and a remote control. This forms a dedicated surround processor (if interested in the software, look at http://www.ludd.luth.se/users/torger/almusvcu.html) for use in multichannel HiFi systems. In some configurations, a 64 sample processing block is relevant, leaving a total IO-delay of 128 samples, which in 44.1 kHz is about 3 ms. With such a configuration, I have got the system going for a few hours at most before underflow. Of course the relevant processes are realtime scheduled, I have even used tricks with sched_yield to get the processes yield in the right order (I will probably have to pay for that sooner or later though) for the most safe operation. So, my question to this list is if someone has run a similar system for days without underflows, and if there is some guide or tips on how to put together the for the moment best low-latency kernel, if there are kernel features that should be avoided, some bad driver or filesystem perhaps, and if there are some hardware setting tricks (apart from giving the sound card the highest interrupt priority). Perhaps tips on which user space processes that should not run (I have no syslogd or cron, but sshd is running) Is it even possible today to build an embedded system with 1.5 ms processing block based on Linux, which runs until hardware or power failure? Oh, my software does not necessarily need to access any filesystem while it is processing, although it would be good if it could (to continuously save volume settings and similar if changed through the remote control). So it can be seen as a strict soundcard-to-the-cpu-and-back problem. /Anders Torger

21 years, 11 months

[linux-audio-dev] |ANN| Autocomp 0.0.5

by Wayne Myers

Hi, Autocomp is an automatic accompaniment generator for Perl and Csound, developed on Linux. It's an attempt at a practice utility for musicians. Freshmeat project page is here: http://freshmeat.net/projects/autocomp/ Download it or read more here: http://www.waz.easynet.co.uk/software.html Currently there is only one style of output, which is a pastiche of a 'swing' style with a walking bassline. The output is heavily on the gorgonzola side of cheesy, but it's already at a stage where you can practice with it if you don't mind the cheese level. All comments/suggestions etc gratefully received. Cheers etc., Wayne -- Wayne Myers http://www.waz.easynet.co.uk/

21 years, 11 months

Re: [linux-audio-dev] Software Setup

by Patrick Shirkey

>Actually I'm just asking because I want to see how good jack is and how >it works before we start to add jack support to glame. Works well for me. Having jack support increases the liklihood of more people using glame too. -- Patrick Shirkey - Boost Hardware Ltd. For the discerning hardware connoisseur Http://www.boosthardware.com Http://www.djcj.org - The Linux Audio Users guide ======================================== Being on stage with the band in front of crowds shouting, "Get off! No! We want normal music!", I think that was more like acting than anything I've ever done. Goldie, 8 Nov, 2002 The Scotsman

21 years, 11 months

[linux-audio-dev] [ANN] ALSA Patch Bay 0.4

by Bob Ham

Mmm.. releases :) Biggest thing is that it now listens to changes in alsa and automatically refreshes. * made a nice dlopen() system for GUIs and drivers * ladcca support * major amounts of code cleaning up and seperating (eg apb.h -> 6 .h's:) * bug fixes * compilation fixes * listens to alsa changes in a thread * gtk gui now uses a proper toolbar with stock buttons http://pkl.net/~node/alsa-patch-bay.html Bob

21 years, 11 months

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Linux-audio-dev December 2002